What is the rubber?

Brief rubber is an add -on and tool used with the boards. These rubber are most commonly used in classes and allow to delete chalk on the board. Eraser is used to rub the surface of a clean plate, remove white or colored dust, from which the chalk is most often made. Thanks to repeatedly usable beefs, erasers are reusable and often have a long -term life. Similar products can come in the form of rubber and branded boards that work similarly to rubber on the board to remove more modern brands from the classroom boards.

The common rubber in the table consists of felt strips that are held together with sticky paper or glue. These felt strips can be accompanied by cardboard pieces between them to ensure a more robust rubber. Felt tips are used as a rubber surface and come into contact with the board to wipe old chalk brands. The rubber is often just a few centimeters long and wide and can usually be pockets in your pants pocket. Several large napkins on the board by mOhlo fill the surface of the rubber with dust, which made it impossible to clean the board. Once the felt surface is dirty, the dust will no longer be removed by the rubber on the board, but moved and blur.

The rubber cleaning on the board is rather primitive and is as simple as the palpitations of the rubber against a solid surface or a metal filter. Eraser can also be cleaned by soaking in warm water. However, this method does not allow immediate use, because the rubber will then have to dry before it is used. Cleaning the rubber by pounding to the surface was popular in the early 20th of the 20th century. Teachers would often do it in the classroom or ask the children to do it, send dust parties to the air. In the end, dust particles proved dangerous and caused sneezing, asthma and limited airways.

For just a few dollars in the United States, rubber in the board is still commonly used in classes or people who have boards at home. Enhancements fromThe minor trolleys of the board, lost the surfaces and added accessories as handles, allowing them to be attached to the back of the hand for faster use.